A battery cell has been proposed as a clean, efficient and environmentally responsible power source for electric vehicles and various other applications. One type of battery cell is known as the lithium-ion battery. The lithium-ion battery is rechargeable and can be formed into a wide variety of shapes and sizes so as to efficiently fill available space in electric vehicles. A plurality of individual lithium-ion battery cells can be provided in a battery pack to provide an amount of power sufficient to operate electric vehicles.
Lithium-ion batteries are known to generate heat during operation and as a result of a charge cycle when recharging. When overheated or otherwise exposed to high-temperature environments, undesirable effects can impact the operation of lithium-ion batteries. Cooling systems are typically employed with lithium-ion battery packs to militate against the undesirable overheating conditions.
As shown in FIG. 1, a state of the art battery pack 2 includes a cooling fin 4 disposed adjacent battery cells 6 for the purpose of transferring heat therefrom. A coolant is generally caused to flow through channels 8 formed throughout the cooling fin 4 for purpose of transferring heat from the battery cells 6. Due to the presence of the channels 8 and the associated ribs on the surface of the cooling fin 4, the state of the art battery pack 2 has undesirably applied a non-uniform pressure to individual battery cells 6, which has now been found to limit the longevity of the battery pack 2. Additionally, due to the presence of the ribs on the state of the art cooling fin 4, the packaging space and volumetric efficiency of the battery pack 2 has been adversely affected.
There is a continuing need for a cooling system and method for maintaining a desired temperature of a battery pack such as a lithium-ion battery pack. Desirably, the cooling system and method provides a uniformly distributed surface pressure to the battery pack while maintaining effective heat transfer therefrom.